Opa is the open platform for building secure, cloud-enabled web applications and web services. Opa is developed by MLstate. To find out more about Opa, please visit opalang.org.

To develop an application in Opa. The theme of the application is entirely up to the creativity of the participants, who will have to choose one of the following eight categories for the submission of their entry:

• Education/Reference Applications
• Games
• Social Networking Applications
• Lifestyle Applications
• Productivity/Tools
• Media and Entertainment Applications
• Travel Applications
• Miscellaneous Applications

The prizes are as follows:

• 1st place: MacBook Air
• 2nd place: iPad 2
• 3rd place: Nintendo 3DS

Additionaly, there will be exclusive Opa goodies - high-end bags, hoodies - for the 3 best applications in each of the eight categories. These items will be exclusively for the Opa contest and will never be made or sold again.

Note that you can develop as many applications as you want, but can only receive a prize for your best rated application.

The judges will equally consider the following criteria:

• Originality of the concept:

  Does the application introduce a great new idea; for example, a new angle on social applications?

• Effective use of the Opa Platform:

  Does the application take advantage of Opa's unique and compelling features?

• Polish and Appeal:

  Is the application easy to use and aesthetically appealing?

• Indispensability:

  Is the application compelling and essential, such as a game the user just can't put down or a utility he can't live without?

Every application will be evaluated by the judges based on the aforementioned criteria and given a score ranging from one to five. The overall score will be the sum of the scores for individual criteria.

Applications will be judged by the following jury:

• Alice Antheaume, Associate director for prospective and international development, school of journalism Sciences Po Paris
• Henri Binsztok, CEO, Founder, MLstate
• Adrien Cahen, Twitter
• Solomon Hykes, CEO, Founder, DotCloud
• Samuel Laurent, Journalist, Blogger at lemonde.fr
• Jorge Ortiz, Foursquare
• Roxanne Varza, Editor-in-Chief, Techcrunch France
• Myles Weissleder, organizer and founder of the SF New Tech Meetup
• Dustin Whittle, Technologist and Open Source advocate

The Opa Developer Challenge is open to both individuals and teams (excluding individuals associated with MLstate, the organizer of the Challenge), whether attached to a business entity or not. All participants must be of legal age at the time of the registration. Participation by teams is allowed, in which case the Team Leader registers on behalf of the team.

You can register here.

The Opa Developer Challenge starts on Wednesday 13 July 2011 GMT and lasts until 23:59, Monday 17 October 2011 GMT.

Here are the terms and conditions.

You will find all the information about Opa on its homepage: opalang.org

Get in touch with us at challenge@opalang.org